Battery knowledge · State estimation
Cell balancing
Equalising the state of charge of cells in series, since the pack is limited by its emptiest cell on discharge and its fullest on charge. Passive balancing bleeds charge from high cells through resistors; active balancing moves it between cells.
Example
Explore the graph
A pack average can hide a cell that reaches its voltage limit first.
Average: 3.93 V. Highest cell: 4.02 V. The highest cell can reach the charge limit first.
V_max = max(V₁, V₂, …); V_average = ΣV_i / N
Illustrative model. The 4.2 V ceiling is an example, not universal. Voltage alone does not uniquely determine SOC.
Use in Lemonergy
Distinguish internal states from noisy measurement estimates.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 3. State and parameter estimation
Gregory L. Plett · Journal of Power Sources · 2004
Topic background · Model-based battery state-of-charge and parameter estimation with extended Kalman filtering, including uncertainty and model dependence.
- Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 2. Modeling and identification
Gregory L. Plett · Journal of Power Sources · 2004
Topic background · Battery charge balance, open-circuit voltage, ohmic loss, polarization dynamics and model identification; parameters require cell-specific data.